Dust-removing device



March 27, 1934. G. A. SCHETTLER 1,952,144

DUST REMOVING DEVICE Filed 1930 4 Sheets-Sheet 1 19 o a: o T2 9 n I TE 39 69 To 60 64 6! 2O 23 o 2 o o o n /NVENTOR March 27, 1.934. A, SCHETTLER Y 1,952,144

DUST REMOVING DEVICE Filed Aug. 21, 1930 4 Sheets-Sheet 2 1 -/Nl/ENTOR W -v v MI March 27, 1934.- e. A. SCHETTLER DUST REMOVING DEVICE Filed Aug. 21, 1930 4 Sheets-Sheet 3 /NVEN TOR Q. S

March 27, 1934. G. A. SCHETTLER 1,952,144

DUST REMOVING DEVICE Patented Mar. 27, 1934 UNITED STATES 1,952,144 DUST-REMOVING DEVICE Gustav Adolf Schettler,

Leeds, England, assignor to The Turner Tanning Machinery Company, Portland, Maine, a corporation of Maine Application August 21,

1930, Serial No. 476,926

In Great Britain August 23, 1929 24 Claims.

This invention relates to dust-removing devices and is shown embodied in a machine for bufiing or fiufiing light leathers. It is to be understood, however, that the inventionand various important features thereof may have other applications and uses.

As heretofore constructed buffing machines, designed for use in leather manufacturing plants, have usually been provided with a dust collecting means comprising an exhaust fan connected with a hood arranged adjacent to a bufling wheel. This arrangement has proved tobe unsatisfactory for the reason that it is of such'low efiiciency that dust from buffing operations fills the air of the operating room, settles upon the finished work and every article in the room, and renders the work of the operator not only difiicult, but injurious to health because of the inhalation of putrescible dust. In fact, in all operating rooms where these bufiing machines are in operation, the operators must wear a dust mask which, of neces sity, renders breathing more difficult at a time when it should be unusually free in view of the exertions which naturally accompany such longcontinued and laborious operations. Not only is the dust-removing means of these. prior constructions ineffioient for the purpose intended but the construction of the buiiing machines has been such as to keep the dust-laden air in circulation both within and around the machine.

Objects of the invention are to increase the efficiency of dust-removing means so that no dust will escape from work-treating machines, and to accomplish this in a self-contained unit whereby dust-removing means of a highly efiicient type becomes a part of each machine.

To these ends and in accordance with. an important feature of the invention, improved means is provided for regulating air currents in withdrawing dust-laden air from a space. closely adjacent to a work treating member and separately from a second space, as at the back of the machine, into which dust-laden air is normally projected during the operations of the work treating member. Conveniently, separate chambers are provided into which dust-laden air is drawn from the vicinity of the work treating member and from the back part of the machine, the dustladen air being withdrawn from these chambers along. independent passageways, an air regulating means for the chamber adjacent to the work treating member being provided in spaced relation. to said chamber. By providing separate chambers for collecting dust-laden air from the immediate vicinity of the work treating member and from another space where dust-laden air is gathered during the operation of the work treating member, better control of both chambers'is secured together with a more highly efiicient removal of the dust from the chambers. In the illustrated construction, the means for regulating the amount of air which may pass into the chamher past the work treating member is located in the other chamber at the back of the machine. This arrangement contributes greatly to the efiiciency of the dust-removing means since the dust is removed directly from the vicinity of the memher which creates the dust, and the force of the air current can be regulated as occasion may require by adjustment of air regulating means located in a place that is safe and accessible during the operation of the machine.

While air withdrawing means of any wellknown type may be used, it is preferred to employ a single exhaust fan of special construction and arrangement for withdrawing air in separate streams from the two chambers mentioned. Con-- veniently, the fan comprises a disk with a set of blades on each side thereof, the disk being arranged to fit snugly and rotatably within an opening in a partition extending across a fan com partment, so that the sets of blades operate in separate sub-compartments to withdraw air in separate streams from the chambers already mentioned. By the use of the special fan in the manner shown, there is obtained an unusually simple and compact construction.

In a preferred embodiment of the invention, the chamber which embraces the work treating member is provided with a casing which is arranged closely to enclose the work treating meme ber, openings in the casing being arranged to furnish communication between the casing and the surrounding chamber. In a construction of this character, the casing with its openings promptly discharges the dust from the work treating member into the surrounding chamber under the suction of the exhaust fan. Where the work treating member is a highspeed rotary member, the casing prevents the dust-laden air within the chamber from being constantly whirled about and disturbed by cross currents so that the dust-laden air is drawn more directly to the exhaust fan. Conveniently, the casing is provided with bafiie plates adjacent each of the openings so that the air is deflected from its tangential course and given a direction toward the stream of air which is passing toward the exhaust fan.

These and other features of the invention and novel combinations of parts will now be described in detail and then pointed out more particularly in the appended. claims.

In the drawings:

Fig. 1 is a perspective view of the complete machine;

Fig. 2 is a similar view of the machine with the cover section raised;

Fig. 3 is a sectional side elevation of the machine frame per se;

Fig. 4 is a plan of the said frame with the cover section removed;

Fig. 5 is a rear elevation-half in section taken on line VV of Figure 4of the frame;

Fig. 6 is a side elevation partly in section of the complete machine;

Fig. 7 is a front elevation-half in section-of the machine;

Fig. 8 is a sectional rear elevation taken on the line VIII-VIII of Figure 6; and

Fig. 9 shows a sectional view taken on line IX-IX of Fig. 6, a detail hereinafter referred to.

In the illustrated machine, which is particularly designed for buffing light leathers, there is provided a frame comprising a lower main section 1 and a hinged upper section 2 constituting a cover for section 1. The main section 1 is in the form of a single box casting (see Figs. 3 to 5) open at the top, and divided into two campartments 3 and 4 by a transverse partition 5 formed substantially midway betweenthe ends of the casting. The cover section 2 also consists of a single casting open at the top and bottom and similarly divided transversely by a partition 6 to form compartments '7 and 8 to correspond with those of the lower section. The two sections 1 and 2 are hinged together at the back, i. e., at 9, and a pro-. jection 10 is provided on the back of the cover 2 for engagement with a stop 11 on the back of the lower section 1 to limit backward movement of the cover when the latter is raised, as shown in Fig. 2. There is thus provided a machine frame having two chambers, one comprising compartments 4 and 8 being behind the other comprising compartments 3 and 7, said chambers being formed partly in the main section 1 and partly inthe cover 2. When the cover 2 is down as shown in Figs. 1 and 3, the lower face thereof makes an air-tight joint with the upper face of the main section 1.

The front chamber contains a wheel 12 which may also be of improved form as will be hereinafter described and the rear chamber contains an exhaust or suction fan unit 13 (Fig. 6) of an improved form as will be hereinafter described. The lower face of the cover and the upper face of the main section are respectively furnished on opposite sides with recesses 14 and 15 (Figs. 3, 6 and 7) which receive bearings 16 for a wheel shaft 17 which latter is mounted in the main section of the frame. Hence, the wheel may be readily removed or replaced as occasion may require. The transverse partition 5 in the main section of the frame has an opening 18 formed therein on one side of the center of the frame as viewed from one end (Fig. 5), so that the wheel compartment 7 communicates with the other compartment 8 as and for a purpose hereinafter set forth.

As shown in Figs. 1, 6 and 7, when the aforesaid cover 2 is down, the wheel 12 projects through a front opening in the top thereof which opening constitutes an air inlet 19 to the wheel chamber. This opening or inlet is restricted so that but slight clearance is provided between the sides thereof and the wheel for the purpose of providing a suction effect in close proximity to the operative portion of the wheel to insure removal of the dust at the source of its formation. Since the suction effect is concentrated in the region where the dust is created it is more effectively removed than heretofore. As shown, the height of the cover at the front is such that only a small segment of the wheel projects from the cover.

The front portions 20 and 21 of the two sections 1 and 2, respectively, of the frame are curved both vertically and horizontally (Figs. 1, 3, 4 and 6) so as to provide a substantially spherical formation and the base portion 22 of the frame is set back to provide a recess 23 thus enabling the operator to place one foot in front of the other to permit him to stand comfortably at his work.

Preferably and as shown, the wheel is provided with an extra close fitting housing or casing 24 (Figs. 2 and 6) formed in halves applied to opposite sides of the wheel and each subdivided diametrically into upper and lower sections 25, 26, secured together by screws 27 and fixed in the wheel chamber by means of screws 28 inserted into lugs 29 (Figs. 3, 4 and 6) in the main section 1. The said halves 25 and 26 of the casing 24 are also secured together by nut and bolt or like fastenings 30. Thus the wheel revolves in this extra housing or casing and not actually in the cham-i her or compartments 3 and '7 in the frame. Because of this arrangement the dust in the wheel chamber 3 is not being constantly circulated by the rotating wheel. The lower section 26 of the casing 24 is formed so as to provide slots or openings 26a through which dust is drawn from the wheel into the compartment 3 when the machine is working, most of the air entering the upper restricted opening in the casing 24 and passing thence into the chamber 3 through the openings 26a. In order that the. air may be drawn into the casing 24 and thence into the chamber 3, the upper edges of the side walls of the compartment '7 hug the adjacent walls of the casing 24 to limit the amount of air entering directly into the compartment 7, as indicated in Fig. 7. At one side of each slot or opening there is a web or flange 2611 serving as a baffle for dust carried round by the wheel. The sections of the casing located concentrically with respect to the periphery of the wheel 12 and between the openings 26a serve to break up the film dust-laden air which has a marked tendency to adhere to the periphery of the wheel. By thus breaking up the film the baflie plates are rendered more effective in removing the dust-laden air from the wheel.

Arranged in the rear compartment 4 is an exhaust or suction fan comprising a rotor disc 31 (Figs. 6 and 8) furnished on opposite sides with fan blades or vanes 32 and rotatable in a sectional casing the sections 33 of which are separated by and attached by nut and bolt fastenings 34 to a partition or plate 35 in which the rotor disc is a running fit so that in effect there are two fans combined in a single unit since said blades or vanes operate in separate casings 36 and 3'7. Each section of the fan casing has a central inlet hole 38 (Fig. 8), and an exhaust pipe 39, common to both sections of the fan casing, extends through an opening 40 (Fig. 6) in a door 41 which closes an opening 42 in the back of the frame section 1, through which the fan unit is inserted into the frame. It is clear, therefore, that a double suction effect is obtained from a single fan unit whereby, in conjunction with the wheel compartment and the compartment at the back of the machine, independent air currents are induced for the purpose of efficiently removing all dustladen air from the machine.

The aforesaid partition or plate 35 is attached to a substantially central web or rib 43 (see Figs. 3, 4, 5, 6 and 8) projecting from the back of the transverse partition 5 in the frame, by which construction the back chamber 4 is subdivided longitudinally into subdivisions or subcompartments 43a and 435 (Fig. 8). Thus as clearly shown in Fig. 8, one section of the fan is in direct communication with subdivision 43b of the compartment 4 and the other section is in communication with the other subdivision 43a (at the left, Fig. 7 and at the right, Fig. 8) and, through the opening 18 in the transverse partition 5 this section of the fan chamber is in communication with the wheel compartment 3 so that there is a direct air passageway from the wheel chamber to the fan. The subdivision 43a which communicates with the wheel compartment 3 is furnished at the top with an air regulator whereby the suction or partial vacuum created in the wheel compartment may be controlled. In other words, the, amount of air passing in through inlet, 19 into the wheel chamber may be regulated by proper adjustment of the air regulator at the top of. subdivision 43a. By having the air regulator spaced from the wheel 12 and wheel chamber 3, adjustment of the air regulating means is facilitated since it is thus located in a safe and readily accessible place. This regulator comprises a fixed member which closes the upper end of said sub,- division and has slots or like openings formed therein, and a movableslotted member whereby the slots or openings in the fixed member can be adjustably covered or uncovered according tov requirements. Conveniently, and as shown, the fixed member is constituted by an inclined or sloping web 44 (Figs. 4, 5, 6 and 8) cast integrally with the frame and provided with parallel slots 45 and the movable member consists of a corresponding slotted plate 46 slidably mounted over the web by means of screws 4'7 inserted into the web 44 through slots 48 in the plate. Since the slots 45 and the plate 46 are in the bottom wall of the compartment 8, the air regulator may be properly described as in the compartment 8.

Hence the air regulator in compartment 8 regulates the intakeof air in wheel compartment 3.

The other subdivision 431) (Fig. 8) is open to the atmosphere at the backof the wheel, 1. e., through the compartment 8 (Figs. 3 and 7) in the cover 2. Hence there is a direct air passageway from the compartment 8 to the fan compartment. An air-tight joint is provided between the pipe 39 and the door 41 by a'felt ring 49 (Fig. 6), and between the plate 35 and the door 41 by a felt packing 50 bedded between two parallel ribs 51 (see particularly Fig. 9) on the door.

As will be understood from the structure described in the preceding paragraph, when the fan rotor is'driven two air currents are induced. That is' to say, air is sucked from the immediately vicinity of the wheel 12 through the restricted wheel opening 19 in the cover, through the wheel compartment 3 and corresponding subdivision 43a of the back compartment 4, and exhausted through the pipe 39 at the back of the machine. Similarly air is sucked into the machine behind the wheel 12, i. e., through. the compartment 8 of the back chamber4 and likewise exhausted through the aforesaid pipe 39. It will be understood that under working conditions the pipe 39 is connected to or with a suitable duct through which the dust is carried to the outside of the building or otherwise suitably disposed of. In this Way the dust created by the machine is efiiciently removed from the space around the wheel 12 and from the spaceat the rear of the machine where it is projected by the rotating wheel, and thereby prevented from spreading in the atmosphere around the machine. The cover 2 is provided with a forwardly extending hood 52 to deflect dust flung off by the wheel, in a direction tangential thereto, into the compartment 8.

The fan rotor is mounted on a shaft 53, Figs. 6., '1 and 8,, suitably mounted in bearings 54 mounted in the sides of the main section of the machine frame.

The blades or vanes 32 on the rotor 21 may be of any suitable form. Conveniently each blade is curved lengthwise, as shown in Fig. 6, and the width thereof increases fora short distance from the root and then decreases gradually towards the outer end or tipas shown in Fig. 8.

Preferably and as shown, the wheel 12 is also of "improved form. Conveniently the wheel is laminated (see Fig. 7) with laminations 55 mounted on, a flanged metal bush or sleeve 56 and clamped, bymeans of nut and bolt fastenings 57, between the flange (not shown) on the sleeve or bush and a loose plate 58 keyed on the sleeve or bush. The sleeve or bush 56 is in turn keyed or otherwise secured on the wheel shaft 17. The wheel 12 can thus be readily removed from the shaft as a whole. The laminations consist of paper, millboard or the like.

The machine is furnished with a main shaft 59 (Fig. '1) from which the wheel shaft 1'7 and fan shaft 53 may be driven in any suitable manner, and any convenient means may be provided for starting and stopping the machine. Conveniently, the main shaft is furnished with fast and loose pulleys 60, 61 (Figs. 1 and 2) the fan shaft 53is driven by a belt 62 and pulleys 63, 64, from the wheel shaft; and the wheel shaft 17 is driven by belt 65 (Fig. '7) and pulleys 66, 67 from the main shaft. In this construction a, belt shipper mechanism, preferably of self-locking type, is provided in association with the fast and loose pulleys and may be operated in any convenient manner. Preferably and as shown, the main shaft 59 is located at the back of the machine and. the belt shipper 68 (Figs. 1 and 2) is operated by means of a handle 69 at the front of the machine through the mediumof a shaft 70, and a link and lever connection (not shown) adapted to lock the shipper against accidental movement in each ofv its two positions.

Another feature, of the machine is that every revolving part is mounted on ball bearings (see, for example, theshafts 17. and 53 and the pulley 61) so as to reduce frictional resistances and consequently loss of power to a minimum. A point in this connection is that by mounting the loose Y pulley 61 on ball bearings the possibility of said pulley seizing on the shaft and thereby starting the machine accidentally is avoided.

The machine is provided with a suitable table for supporting the leather which overhangs the wheel during the operation of the machine. Conspectively, on opposite sides of the cover section 2 the cover- 2, through. the other. subdivisiom43ob adjacent, to the wheel.

veniently, separate wooden. tables 71 (Figs. 1, 2 and 6) are mounted by means of brackets '72, re-

To prevent the leather from being sucked into the machine through the entrance to the back compartment 8, i. e., between the wheel 12 and the hood 52 on the cover section, in the event'of the operative losing his grip thereon, a wire or like grid or fence is provided at or in the entrance to said compartment. Conveniently, the grid or fence consists of a series of parallel wires or metal rods 73 extending across the said entrance as shown in Figs. 1 and '7.

As will be readily understood the present invention provides a simple and compact builing and fiufiing machine which is capable of eificiently removing the dust created by the action of the wheel on the leather and by which the desired operation can be very readily performed with a minimum of fatigue and discomfort to the operator.

In the operation of the machine the abrasive wheel 12, turning in a clockwise direction as viewed in Figs. 1 and 6, will operate to grind away portions of a piece of leather pressed upon the wheel 12 while it is held in the hands of the operator. During the grinding operation particles of leather removed from the under surface of the piece of leather will be carried ofi in the form of dust and some of these particles will travel with the wheel 12 into the casing 24 while other par ticles will be projected into the hood 52 of the dust collecting chamber 8. Those particles of dust which enter the casing 24 are withdrawn from the casing through openings 26a into the wheel chamber 3 from which they pass through an opening 18 into the compartment 43a and thence through the opening 38 into the fan compartment 3'7 and from there to the outlet 39 (Fig. 6). The particles which are projected from the wheel 12 into the chamber 8 pass directly to the compartment 432) (Fig. 8) and then through the opening 38 into the fan compartment 36 and thence to the outlet 39. It is clear from the foregoing description that the dust particles from the seat of operations upon pieces of work are carried along two difierent passageways to the outlet 39 accordingly as they enter the casing 24 in the wheel chamber 3 or the chamber 8 below the hood member 52.

' Having described my invention, what I claim as new and desire to secure by Letters Patent of the United States is: a

1. In a machine for treating work in the operation of which dust is formed, a work treating member rotatable at high speed in a directionaway from the operator so that dust particles produced in work treating operations are projected in a direction tangential to the work treating member and away from the operator, a chamber for collecting dust in thevicinity of the work treating member, a second chamber for collecting dust projected tangentially into space at one side of the first-mentioned chamber, means for withdrawing dust-laden air from the chambers, individual air passageways for conducting air from the chambers separately to the air withdrawing means, and air regulator means for one chamber located in the other chamber.

2. In a machine for treating work in the operation of which dust is formed, a member for treating a piece of Work, a chamber for partially ation, and air regulator means spaced with respect to, and independent of, said air inlet for controlling adjustably the amount of air passing into the chamber through said inlet.

3. In a machine for treating work in the operation of which dust is formed, a member for treating a piece of work, a chamber for partially enclosing said work treating member, the walls of the chamber being spaced closely adjacent to the work treating member to form an inlet for air into the chamber, means for withdrawing air from the chamber during the work treating operation, and air regulator means located on the side of said air withdrawing means away from said chamber for controlling adjustably the amount of air passing into the chamber through said inlet. 7

4. In a machine for treating work in the operation of which dust is formed, a member for treating a piece of work, a chamber for partially enclosing said work treating member, the walls of the chamber being spaced closely adjacent to the work treating member to form an inlet for air into the chamber, means for withdrawing air from the chamber during the work treating operation, a compartment in which is located the air-withdrawing means, a connecting air passage between the chamber and compartment comprising an air inlet into the compartment, said compartment having an outlet through which dust-laden air is discharged and also another air inlet, and means for controlling the entrance of air into the last-mentioned air inlet whereby the amount of air entering the first-mentioned air inlet may be regulated.

5. In a m chine for treating work in the operation of which dust is formed, a member for treating a piece of work, a chamber for partially enclosing said work treating member, the walls of the chamber being spaced closely adjacent to the work treating member to form an inlet for air into the chamber, means for withdrawing air from the chamber during the work treating operation, an exhaust fan, a compartment for the fan, a connecting air passage between the chamber and compartment comprising an air inlet into the compartment, the latter having an outlet through which dust-laden air is discharged and also another air inlet, and a movable plate for controlling entrance of air through-the last-men tioned air inlet whereby the amount of air entering the first-mentioned air inlet may be regulated.

6. In a machine for treating work in the operation of which dust is'formed, a work treating member, a chamber for partially enclosing the work treating member and having an inlet for air around said member, a second chamber located at one side of the first-mentioned chamber, said second chamber being non-communicating with respect to the other chamber and 1 having its own inlet and outlet for air, means for removing air simultaneously from both chambers, and means located in one chamber for regulating the intake of air into the other of said chambers.

'7. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a chamber for partially enclosing the work treating member, said chamber having portions closely spaced with respect to the rotary work treating member where the latter projects from the chamber to form an inlet for air past the work treating member, a second chamber located at one side of the first-mentioned chamber in the direction of rotation of the rotary treating member, a suction fan 'for removing air simultaneously from both chambers, a compartment for enclosing the fan, an air passageway between each chamber and said compartment, an air inlet on the side of the fan away from one of said chambers to control the intake of air into said one of the chambers, and a member adjustable to vary the size of said inlet.

8. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a chamber for partially enclosing the work treating member, said chamber having portions closely spaced with respect to the rotary work treating member where the latter projects from the chamber to form an inlet for air past the work treating member, a second chamber located at one side of the first-mentioned chamber in the direction of rotation of the rotary treating member, said second chamber being non-communicating with respect to the other chamber and having its own inlet and outlet for air, a suction fan for removing air simultaneously from both chambers, and means located in the second chamber for regulating the intake of air at said inlet opening into the firstmentioned chamber.

9. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a chamber for partially enclosing the work treating member, said chamber having portions closely spaced with respect to the rotary work treating member where the lat ter projects from the chamber to form an inlet for air past the work treating member, a second chamber located at one side of the first-mentioned chamber in the direction of rotation of the rotary treating member, said second chamber being non-communicating with respect to the other chamber and having its own inlet and outlet for air, a suction fan for removing air from both chambers, and means spaced with respect to the inlet of the first mentioned chamber for adjustably regulating the amount of air passing through said inlet into the first-mentioned chamber.

10. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a chamber for partially enclosing the work treating member, said chamber having portions closely spaced with respect to the rotary work treating member where the latter projects from the chamber to form an inlet for air past the work treating member, a second chamber located at one side of the first-mentioned chamber in the direction of rotation of the rotary treating member, a suction fan for removing air simultaneously from both chambers, a compartment for the fan, and means in the wall of the fan compartment for regulating the amount of air passing through said inletinto the first-mentioned chamber.

11. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a chamber for partially enclosing the work treating member, said chamber having portions closely spaced with respect to the rotary work treating member where the latter projects from the chamber to form an inlet for air past the work treating member, a second chamber located at one side of the firstmentioned chamber in the direction of rotation of the rotary treating member, a suction fan for removing air from both chambers, a compartment for the suction fan, an air passageway between each chamber and the fan compartment comprising an inlet into said fan compartment, said compartment having an outlet and another air inlet, and means for varying the amount of air entering the fan compartment through said last-mentioned inlet thereby to regulate the amount of air entering through said inlet into the first-mentioned chamber.

12. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a chamber for partially enclosing the work treating member, said chamber having portions closely spaced with respect to the rotary work treating member where the latter projects from the chamber to form an inlet for air past the work treating member, a second chamber located at one side of the first-mentioned chamber in the direction of rotation of the rotary treating member, a suction fan for removing air from both chambers, a compartment for the suction fan, the first-mentioned chamber and the fan compartment having a connecting air passage comprising an inlet to said compartment, the fan compartment having another air inlet, and a movable plate for varying the amount of air entering the fan compartment through said last-mentioned inlet thereby to regulate the amount of air entering through said inlet into the first-mentioned chamber.

13. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a chamber for partially enclosing the work treating member, said chamber having portions closely spaced with respect to the rotary work treating member where the latter projects from the chamber to form an inlet for air past the work treating member, a second chamber located at one side of the first-mentioned chamber in the direction of rotation of the rotary treating member, a suction fan for removing air simultaneously from both chambers, a compartment for the suction fan having a partition for dividing the fan chamber into two sub-compartments, the first-mentioned chamber being connected with one sub-compartment and the second-mentioned chamber with the other sub-compartment, the fan compartment having an outlet through which air is ejected from both sub-compartments during rotation of said fan.

14. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a casing arranged partially to enclose said member and having portions spaced closely with respect to the rotary member to provide a restricted inlet for airinto the casing, a chamber surrounding the casing, said chamber having walls the edges of which fit snugly against the walls of the casing to minimize the amount of air entering directly into said chamber, and said casing having openings leading into the chamber, bafiie plates arranged adjacent to the openings, and means for withdrawing air from the easing into said chamber.

15. In a machine for treating work in the operation of which dust is formed, a rotary work treating member, a chamber arranged partially to enclose the work treating member, a casing within the chamber having all portions thereof closely spaced with respect to the enclosed work treating member so as to provide a relatively restricted space about said member, said chamber having walls the edges of which fit snugly leading into the'chamber, baffle 'plates'adjacent said openings, and suction means for withdrawing dust-laden air from said chamber.

16. In a machine for treating work in the operation of which dust is formed, a treating member, a casing for partially enclosing the work treating member, said casing having walls closely spaced with respect to the work treating member to provide a space within the casing and about the treating member, said casing having portions closely spaced with respect to the work treating member where the latter projects from the casing to provide a restricted inlet for air passing into the casing, a chamber surroundin the casing, said chamber having Walls the edges of which fit snugly against the walls of the casing to minimize the amount of air entering directly into said chamber, and said casing having openings into the chamber, whereby dustcarrying air enters the chamber through said casing, and means for withdrawing air continuously from the chamber during operation of the work treating member.

17. In a machine for treating work in the operation of which dust is formed, a rotary treat ing member, a casing for partially enclosing the work treating member, said casing having walls closely spaced with respect to the work treating member to provide a relatively limited space within the casing within which the work treating member rotates, a chamber surrounding the casing, said casing having portions projecting beyond said chamber and arranged in closely spaced relation with respect to the work treating member where the latter projects from the casing to provide a restricted inlet for air passing into the casing, said chamber having walls the edges of which fit snugly against the walls of the casing to restrict the amount of air entering directly into said chamber, and said casing having an opening into the chamber, whereby dust-carrying air enters the chamber through the casing, means for withdrawing air continuously from the chamber during rotation of the work treating member, and means for regulating the amount of air passing through the inlet into the casing.

18. In a machine for treating work in the operation of which dust is formed, a rotary treating member, a casing for partially enclosing the work treating member, said casing having walls closely spaced with respect to the work treating member to provide a relatively limited space within the casing within which the work treating member rotates, a chamber surrounding the casing, said casing having portions projecting beyond said chamber and arranged in closely spaced relation with respect to the work treating member where the latter projects from the casing to provide an inlet for air passing into the casing, said chamber having walls the edges of which fit snugly against the walls of the easing to restrict the amount of air entering directly into said chamber, and said casing having an opening into the chamber, whereby dustcarrying air enters the chamber through the casing, means for withdrawing air continuously from the chamber during rotation of the work treating member, and means spaced from the air inlet for regulating the amount of air passing into the casing through said inlet.

19. In a machine for treating work in the operation of which dust is formed, a rotary treating member, a casing for partially enclosing the work treating member, said casing having walls closely spaced with respect-to the work treating member to provide a space within the casing within which the work treating member rotates, said casing having portions closely spaced with respect to the work treating member where the latter projects from the casing to provide a restricted inlet for air passing into the casing, a chamber surrounding the casing, said chamber having walls the edges of which fit snugly against the walls of the casing to restrict the amount of air entering directly into said chamber, and said casing having an opening into the chamber, whereby dust-carrying air enters the chamber through the casing, means for withdrawing air continuously from the chamber during rotation of the work treating member, a compartment for enclosing said air withdrawing means, an air passageway between the chamber and the compartment, an inlet to the compartment, and means for varying the amount of air entering the compartment through the last-mentioned inlet to regulate the amount of air entering the inlet into the casing.

20. In a machine for treating work in the operation of which dust is formed, a work treating chamber, a chamber for partially enclosing the work treating member and having portions closely spaced with respect to the work treating member to form an inlet for the passage of air into said chamber, said chamber being provided for the collection of dust caused by the work treating operations, a second chamber located in spaced relation to the first-mentioned chamber for withdrawing dust-laden air from the work treating member, a rotary disk having two sets of blades on opposite sides thereof and operative during rotation to draw air from both chambers, a compartment surrounding the bladed disk and having a partition with an opening snugly fitting said disk to provide a sub-compartment on each side of the partition, a set of blades on eachside of the disk operating in its respective sub-compartment, and air passages between the firstmentioned chambers to the sub-compartments whereby air may be withdrawn from the chambers into the sub-compartments to be discharged therefrom.

21. In a machine for treating work in the operation of which dust is formed, a work treating member, a chamber for partially enclosing the work treating member and having portions closely spaced with respect to the work treating member to form a restricted inlet for the passage of air into said chamber, said chamber being provicled for the collection of dust caused by the work treating operations, a second chamber located in spaced relation to the first-mentioned chamber for withdrawing dust-laden air from the work treating member, a rotary disk having two sets of blades on opposite sides thereof and operative during rotation to draw air from both chambers, a compartment surrounding the bladed disk and having a partition with an opening snug- 1y fitting said disk to provide a sub-compartment on each side of the partition, a set of blades on each side of the disk operating in its respective sub-compartment, air passages between the firstmentioned chambers and the sub-compartments whereby air may be withdrawn from the chambers into the sub-compartments to be discharged therefrom, and means for regulating entrance of air into that sub-compartment which is connected with the first-mentioned chamber.

22. In a machine for treating work in the operation of which dust is formed, a work treating member, a chamber for partially enclosing the work treating member for the collection of dust caused by the work treating operations, a second chamber located in spaced relation to the first-mentioned chamber for withdrawing dust-laden air from the vicinity of the work treating member, a rotary disk having two sets of blades on opposite sides thereof and operative during rotation to draw air from both chambers, a compartment surrounding the bladed disk and having a partition with an opening snugly fitting said disk to provide a sub-compartment on each side of the partition, the set of blades on each side of the disk operating in its respective sub-compartment, and air passages between the first-mentioned chambers and the sub-compartments whereby air may be withdrawn from the chambers into the sub-compartments to be discharged therefrom.

23. In a machine for treating work in the operation of which dust is formed, a work treating member, and means for withdrawing air from two spaces, one being adjacent to said member, said means comprising a rotary disk having blades on opposite sides thereof and operative during rotation to draw air from both spaces, a compartment surrounding the bladed disk and having a partition with an opening snugly fitting said disk toprovide a sub-compartment on each side of the partition, the blades on each side of the disk operating in their respective sub-compartments, air passages between the said spaces and the sub-compartments whereby air may be withdrawn from the spaces into the sub-compartments to be discharged therefrom.

24. In a machine for treating work in the operation of which dust is formed, a rotary disk having blades on opposite sides thereof, and a compartment for enclosing the bladed disk, the compartment being provided with a partition having an opening within which the said disk is snugly fitted so that sub-compartments are provided on each side of a wall formed by the partition and disk, the compartment having an outlet, and an inlet into each sub-compartment so that the bladed disk may draw upon air from separate sources and discharge it through one outlet.

GUSTAV ADOLF SCHETTLER. 

